Control units built to aerospace quality are often required to pass a dielectric test after being fabricated and prior to implementation in an aerospace environment. The dielectric test procedure entails applying high voltage in the range of 1500 V AC for a certain period of time to all mutually isolated terminals, and also from those terminals to the chassis that contains and encloses the printed circuit boards and circuit assemblies of the control unit. In many cases, filter circuits, such as lightning mitigating circuits and common mode filtering circuits and assemblies, are connected between the control units and ground or the chassis. The filtering circuits have relatively low impedance to the chassis potential. In order to pass the dielectric test, those circuits are typically removed from the printed circuit board or from the control box prior to conducting the dielectric test. Once the test is completed, those elements are reinstalled onto the printed circuit board or control box. This extra step in the manufacturing process is undesirable as it introduces manual labor to a process that is normally automated, increasing cost and the likelihood of errors.